Note: Section A is compulsory. Attempt any four questions
from Section B and any two from Section
C.

Section-A

1.

a) What is Supercharging?

b) What is octane number?

c) What is polytrophic work?

d) What is turbojet engine?

e) What is stalling?

f) What is propulsion Efficiency?

g) Draw Brayton cycle.

h) Define turbine efficiency.

i) Why intercooling is done?

j) What is Turbojet?

Section-B

2. What are the three methods of generating swirl in CI
engine combustion chamber?

3. Explain the stages of combustion in a CI engine.

4. A gas turbine plant works between the fixed adiabatic
temperature limits 3000°K and 900°K, the
absolute pressure limits being 1 kgf/cm2
and 4kgf/cm2. The isentropic efficiency of the blower is 0.8 and that of turbine is 0.85.
Estimate the actual thermal efficiency of the plant. Calorific value is 10,000 kcal/kg.

5. The air enters the compressor of a gas turbine at
atmospheric pressure and 30°C and is
compressed to 6kgf/cm2 with an isentropic efficiency of 85%. The turbine
inlet temperature is 500°C. The
isentropic efficiency of the turbine is 80%. Estimate the flow of air in kg/s
for a net h.p. of 2000.

6. What are the various methods which are used to improve
the efficiency and output of a gas
turbine?

Section-C

7. Explain the working principle of centrifugal compressor
with the help of h-s chart. What do you
mean by diffuser efficiency?

8. (a) The following data are given for a centrifugal
compressor and it is required to find the
impeller tip diameter:

(b) Discuss the
surging in the case of centrifugal and axial flow compressor.

9. (a) Air at temperature of 15°C enters a gas turbine plant
working at pressure ratio of 5. Turbine
inlet temperature is 800°C. Polytropic efficiency of compressor and turbine is
0.87. Assume cp = 0.24 for air and gases
and calorific value of fuel used = 10,000 kcal/kg of fuel.